anyone can fix my alpine 3566 amp before i put it up for sale?

first and foremost i'm not looking to spend alot to get it repaired. alpine charges $70 flat repair, but i was looking for something less. anyhow it's an alpine 3566. channel 4 and 6 are cutting off and on, mainly off. known problems with these 35xx amps. but everythign else works. think it might be an easy fix, since the channels are still working, just off and on. anyhow im either getting it repaired, or just selling it ..but i'd rather get it repaired if possible.